The present invention relates to a particle-impact localizing device. It also relates to cathode-ray oscilloscopes and pick-up tubes comprising such a device.
In the prior art devices are known for localizing the x and y coordinates of an emissive point P based on the following principle.
Starting with a rectangular plate made from a material of uniform resistivity, two opposite sides of which are edged with an electrode made from a weakly resistive material, a current is injected at any point P on this plate by means of a DC voltage source connected between the plate and the electrodes. It is known that there will flow in each electrode currents i.sub.1 and i.sub.2 such that the x coordinate of point P, along an axis 0x perpendicular to the electrodes, is written: EQU x=(i.sub.1 -i.sub.2)/(i.sub.1 +i.sub.2).
To know the y coordinate of point P along as axis 0y perpendicular to 0x, it is sufficient to dispose on the plate two other electrodes perpendicular to the first ones and to inject a current at point P using these electrodes. The y coordinate of point P is written as a function of currents i'.sub.1 and i'.sub.2 which flow in these electrodes: EQU y=(i'.sub.1 -i'.sub.1)/(i'.sub.1 +i'.sub.2).